1. Field of the Invention
The present invention is directed to a receiver, specifically a digital microwave receiver (DMR) with improved spectral dynamic range and reception instantaneous bandwidth.
2. Description of Related Art
Most tracking radar systems not intended for space applications operate in the range of 2 GHz to 20 GHz, although search radars often operate in lower bands, and have an instantaneous bandwidth (IBW) on the order of 1 to 10 MHz. Electronic Warfare (EW) receivers need to rapidly acquire such radar signals, so a narrow band IBW tuneable superheterodyne detector is not appropriate by itself.
EW receivers with wide IBW's have been employed, such as crystal video receivers and digital instantaneous frequency measurement (IFM) receivers. However, the signal environment is quite complex, especially if viewed over a wide band, and includes low, medium and high duty cycle signals. The present wide band EW receivers cannot accurately provide information when pulse signals are simultaneously present, especially for the weaker of the simultaneous signals. Simultaneous signals cause the sensor to be blinded or generate false data.
To achieve the requirement for both fine selectivity and wide reception, the use of many channels, each with a high sensitivity detector, is advocated. But, even if a large number of channels is proven practical, the subsequent processing of the received signals will be overwhelmed with data.
The economic impact of having many channels is presently minimized by employing parallel receiver hardware, employing a variety of receiver types and multiplexing receivers across the band.